Methods of power injecting a fluid through an access port

ABSTRACT

Methods of power injecting a fluid through an access port are described. One method includes implanting in a patient an access port suitable for passing fluid therethrough at a rate of at least about 1 milliliter per second, the access port including a body defining a cavity, a septum, and an outlet in fluid communication with the cavity, and flowing a fluid through an infusion set into the access port at a rate of at least about 1 milliliter per second, the infusion set including a needle in fluid communication with a tubing, the tubing in fluid communication with a connector, each of the needle, tubing, and connector constructed to have a burst pressure of at least about 100 psi.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.11/380,124, filed Apr. 25, 2006, which claims the benefit of priority toU.S. Provisional Patent Application No. 60/737,466, filed Nov. 15, 2005,and to U.S. Provisional Patent Application No. 60/675,309, filed Apr.27, 2005, each of which applications is hereby incorporated by referencein its entirety into this application.

BACKGROUND

A wide variety of medical procedures require infusion of a fluid into apatient. For example, vascular imaging technologies may require use of acontrast media that is injected into the patient. More specifically,computed tomography (CT) is an imaging technology that utilizes acontrast media and may be employed for the noninvasive evaluation andassessment of a vascular system (i.e., CT angiography or CTA).Multidetector computed tomography (MDCT) is one specific type of CT thatmay be utilized for CTA. For proper imaging of a vascular system via CT,intravenous contrast media injection protocols are coordinated andselected for the anatomic area of interest.

More particularly, conventionally, a so-called “power injector” systemmay be employed for injecting contrast media at a high pressure into aperipherally inserted intravenous (IV) line. For example, such powerinjectors or injection systems may be commercially available fromMedrad, Inc., a subsidiary of Schering AG, Germany and may be marketedas STELLANT® injection systems. Because CT procedures are often definedin terms of a desired flow rate of contrast media, such power injectionsystems are, in general, controllable by selecting a desired flow rate.Accordingly, such power injection systems may develop pressure (withinthe maximum pressure capability of the power injection system) as isnecessary to maintain the selected flow rate. Accordingly, as may beappreciated, obstructions in the IV lines or use of IV lines that arenot structured to withstand the pressures of a desired injection ratemay cause the power injector to generate a pressure that exceeds asuitable pressure limit for the IV line. After intravenous injection, abolus of contrast material, may flow within the vascular system of thepatient to the right side of the heart, through the lungs, into the leftside of the heart, and through the remaining circulatory system. Afterthe bolus of contrast media is injected into the patient, portions ofthe contrast media may remain in the right side of the heart. Thus, theoverall effectiveness of contrast enhancement may depend on a multitudeof factors. For example, a patient's characteristics (e.g., body size;circulation, including cardiac output and circulating volume, and renalfunction), the contrast characteristics (e.g., volume, injection rate,iodine concentration, etc.), and the CT technique (e.g., access androute of administration, scan delay, scan speed, and injection pattern)may each influence the overall degree of contrast enhancement.

By way of background, conventionally, relatively long scan times havebeen accompanied by relatively long contrast media delivery times.However, because scan times continue to decrease, relatively fastdelivery of contrast media may be desired. Explaining further, incoronary CTA, a large enough volume of contrast material must beadministered at a sufficiently high rate to reach and maintain asuitable concentration throughout a selected scan time (e.g., a 15second scan time), and within a selected region of the anatomy (e.g., anaxial scan distance of 20 cm, which may include the left ventricle andoutflow tract). It also may be desirable that contrast density valuesare sufficient to facilitate the segmentation techniques used inmultidimensional post-processing. A typical contrast media used incoronary CTA may have an iodine density of about 300 milligrams permilliliter to about 350 milligrams per milliliter. Also, since contrastmedia may be radioactive, reducing the overall quantity of contrastmedia required to perform an imaging process may be advantageous.

The pressure required for contrast injection depends on many factors,including flow rate, contrast viscosity, configuration of infusiontubing, such as tube diameter and length, and any obstruction orrestriction to flow (e.g., kinks, curves, fittings, compression). Asmentioned above, to maintain the flow rate required for a CT or MRIstudy, a power injector may generate high pressures. Ruptures can occurwhen the injection pressure exceeds the tolerance of the vascular accessdevice(s). Other problems may occur due to timing errors between thescan and the contrast. In order to maximize the rapid scanning capacityof the newer vascular imaging devices, the starting of the scanningprocess can be delayed a predetermined amount of time after injection ofthe contrast media has begun. If the scan starts too early, just as thecontrast is arriving at the heart, arteries can appear smaller than theyreally are when the image is post-processed. On the other hand, ifscanning is delayed too long, image artifacts can arise from dilutedcontrast in the cardiac veins. The window of opportunity for optimalscans may be very small, because contrast media circulates quicklythrough cardiac arteries and into cardiac veins.

Some diagnostic or medical procedures may advantageously employ asubcutaneous vascular access port for introducing a fluid into thevasculature of a patient. Access portals, or ports, provide a convenientmethod to repeatedly deliver medicants to remote areas of the bodywithout utilizing surgical procedures. The port is implantable withinthe body, and permits the infusion of medications, parenteral solutions,blood products, contrast media, or other fluids. Additionally, the portmay be used to aspirate blood from the patient. Such access portstypically include a cannula-impenetrable housing which encloses one ormore fluid cavities or reservoirs and defines for each such fluid cavityan access aperture communicating through the housing. Acannula-penetrable septum is positioned adjacent to and seals eachaccess aperture. An outlet stem communicates with one or more of thefluid cavities for dispensing medication therefrom to a predeterminedlocation in the body of the patient through an implanted catheterattached to the access port. Once the access port and the catheter havebeen implanted beneath the skin of a patient, quantities of fluid, suchas medication, blood, etc., may be dispensed through one such fluidcavity by, for example, a cannula (e.g., a needle), passed through theskin of the patient and penetrating the septum into one of therespective fluid cavities. This medication is directed through thedistal end of the catheter to an entry point into the venous system ofthe body of the patient. Further, blood may be aspirated through thesubcutaneous access port. Thus, use of an access port may allow forvascular access without needle sticks into the vasculature of a patient.

However, conventional access ports and attendant infusion systems havenot been suitable for performing power injection.

Particularly, the use of power injection systems in combination withconventional vascular access ports has achieved less than ideal results.Thus, it may be appreciated that vascular access ports for infusionsystems and infusion-related apparatuses structured for performing powerinjection may be advantageous.

SUMMARY

One aspect of the instant disclosure relates to a method of flowingfluid through an access port. More particularly, a vascular access portmay be provided and a fluid may be caused to flow through the accessport at a rate of at least about 1 milliliter per second.

A further aspect of the instant disclosure relates to a method offlowing fluid through an infusion set. For example, an infusion set maybe provided and a fluid may be flowed through the infusion set at a rateof at least about 1 milliliter per second.

Another aspect of the instant disclosure relates to an access port forproviding subcutaneous access to a patient. Specifically, an access portmay comprise a housing defining an aperture for capturing a septum,wherein the housing and septum define a reservoir. In addition, theseptum may include a tenon region wherein the housing of the access portdefines a complimentary mortise region structured for accepting at leasta portion of the tenon region of the septum. Optionally, the housing mayinclude a ring structure proximate to at least a portion of a sideperiphery of the septum.

An additional aspect of the instant disclosure relates to an access portfor providing subcutaneous access to a patient. In one embodiment, anaccess port may comprise a housing defining an aperture for capturing aseptum, the housing and septum defining a reservoir. In addition, thehousing and septum may be structured for accommodating a flow ratethrough the reservoir of at least about 1 milliliter per second. Inanother embodiment, an access port may include a housing and septum, asdescribed above, wherein the housing and the septum are structured foraccommodating a pressure developed within the reservoir of at leastabout 35 psi.

Yet another aspect of the instant disclosure relates to an infusion setfor use in subcutaneously accessing a patient. For example, in oneembodiment, an infusion set may comprise a tubing section defining alumen and a cannula in fluid communication with the lumen of the tubingsection. Also, the cannula may be configured for insertion through aseptum of an access port, and the tubing section and the cannula may bestructured for allowing a fluid to flow at a rate of at least about 1milliliter per second. Optionally the cannula may be configured forpuncturing a septum of an access port and the tubing section and thecannula may be structured for accommodating a pressure of at least about400 psi. For example, the tubing section and the cannula may bestructured for accommodating a pressure of about 600 psi.

A further aspect of the instant disclosure relates to infusion tubingfor use in accessing a vascular system of a patient. In one embodiment,infusion tubing may comprise a plurality of layers, wherein the tubingis structured for accommodating a fluid flow rate of at least about 1milliliter per second. In another embodiment, infusion tubing maycomprise a plurality of layers, wherein at least one layer of theplurality of layers extends beyond at least another of the plurality oflayers and is structured for forming a cannula for puncturing a septumof an access port. In yet an additional embodiment, an infusion set foruse in subcutaneously accessing a patient may comprise a tubing sectiondefining a lumen and a cannula in fluid communication with the lumen ofthe tubing section, wherein the cannula is configured for insertionthrough a septum of an access port. Additionally, the tubing section andcannula may be structured for accommodating a pressure of at least about400 psi.

Another aspect of the instant disclosure relates to a method ofidentifying an access port as being suitable for power injection. Morespecifically, an access port including a septum may be provided.Further, the access port may be identified as being suitable for powerinjection.

Yet a further aspect of the instant disclosure relates to an access portfor providing subcutaneous access to a patient. Particularly, an accessport may comprise a housing configured for capturing a septum, theseptum configured for inserting a cannula therethrough and into areservoir defined within the housing and at least one structural elementconfigured for resisting deformation of the septum in response to apressure developed within the reservoir.

In an additional aspect of the instant disclosure, a method of operationof an access port may comprise providing a housing configured forcapturing a septum, the septum configured for inserting a cannula (whichcan include a needle, a Huber needle, a trocar with an associatedcannula, or any combination thereof) therethrough and into a reservoirdefined within the housing, and developing a pressure within thereservoir of the housing. Further, such a method may comprise limitingdeformation of the septum in response to the pressure developed withinthe reservoir.

In addition, one aspect of the instant disclosure relates to a septumcomprising a gel or a viscous liquid. For example, in one embodiment, aseptum for assembly with a housing to form an access port for providingsubcutaneous access to a patient may comprise a body including an uppersurface and a lower surface and at least one gel region positionedgenerally between the upper surface and the lower surface. Anotherembodiment may comprise a septum for assembly with a housing to form anaccess port for providing subcutaneous access to a patient may comprisea body, a layer formed over at least a portion of the body, and a gelregion positioned at least partially between the layer and the body.

The above-described infusion apparatuses and related methods may bebeneficially employed for effecting or facilitating power injectionprocesses. For instance, such methods and apparatuses may be employedfor infusing a fluid (e.g., a contrast media) at a rate of between about1 milliliter per second and about 5 milliliters per second.

Features from any of the above mentioned embodiments may be used incombination with one another in accordance with the instant disclosure.In addition, other features and advantages of the instant disclosurewill become apparent to those of ordinary skill in the art throughconsideration of the ensuing description, the accompanying drawings, andthe appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Advantages of the instant disclosure will become apparent upon review ofthe following detailed description and drawings, which illustraterepresentations (not necessarily drawn to scale) of various aspects ofthe instant disclosure, wherein:

FIG. 1 shows an exploded, perspective view of an access port accordingto the instant disclosure;

FIG. 2 shows a schematic, side cross-sectional view of the access portshown in FIG. 1;

FIG. 3 shows a schematic, top elevation view of a cap including a ringfeature as shown in FIGS. 1 and 2;

FIG. 4 shows a schematic, top elevation view of another embodiment of acap including a ring feature;

FIG. 5 shows a schematic, top elevation view of a further embodiment ofa cap including a ring feature;

FIG. 6 shows a schematic, side cross-sectional view of an implantedaccess port with a cannula extending through the septum of the accessport;

FIG. 7 shows a graph depicting pressures at selected regions within aninfusion system for a given flow rate;

FIG. 8 shows a schematic, side cross-sectional view of an access portincluding a septum with a tenon region and a housing with a mortiseregion;

FIG. 9 shows a schematic, side cross-sectional view of anotherembodiment of an access port including a septum with a tenon region anda housing defining a mortise region;

FIG. 10 shows a schematic, side cross-sectional view of a furtherembodiment of an access port including a tenon region and a housingdefining a mortise region;

FIG. 11 shows a schematic, side cross-sectional view of an access port,wherein at least a portion of a side periphery of the septum is affixedto the housing;

FIG. 12 shows a schematic, side cross-sectional view of an access portincluding a structural element extending between the septum and thehousing;

FIG. 13 shows a schematic, side cross-sectional view of an access portincluding a structural element with a barbed end positioned within theseptum;

FIG. 14 shows a schematic, side cross-sectional view of an access portincluding a structural element extending between an upper surface of theseptum and the housing;

FIG. 15 shows a schematic, side cross-sectional view of an access portas shown in FIG. 14 and also including a support element positionedadjacent to an upper surface of the septum;

FIG. 16 shows a schematic, side cross-sectional view of an access portincluding a septum with an extension leg that extends to the housing;

FIG. 17 shows a schematic, side cross-sectional view of an access portincluding a septum with an extension leg comprising an enlarged end thatcouples to a recessed form in the housing;

FIG. 18 shows a schematic, side cross-sectional view of an access portincluding a septum in a structural element positioned adjacent to anupper surface of the septum;

FIG. 19 shows a schematic, side cross-sectional view of an access portincluding a septum and a structural element extending laterally throughthe septum;

FIG. 20 shows a schematic, side cross-sectional view of an access portincluding a septum and a structural element positioned proximate to anupper surface of the septum;

FIG. 21 shows a schematic, side cross-sectional view of an access portincluding a septum and a structural element positioned proximate to alower surface of the septum;

FIG. 22 shows a partial, top elevation view of an access port, as shownin FIGS. 18-21, wherein structural elements are arranged in a generallytriangular pattern;

FIG. 23 shows a partial, top elevation view of an access port, as shownin FIGS. 18-21, wherein structural elements are arranged in twogenerally rectangular patterns;

FIG. 24 shows a partial, top elevation view of an access port, as shownin FIGS. 18-21, wherein structural elements are arranged in a firstplurality of substantially parallel lines and a second plurality ofsubstantially parallel lines;

FIG. 25 shows a partial, top elevation view of an access port as shownin FIGS. 18-21, wherein structural elements are arranged as twointersecting substantially straight members;

FIG. 26 shows a partial, top elevation view of a septum including astructural element positioned within the septum;

FIG. 27 shows a perspective view of a sectioned septum, as shown in FIG.26;

FIG. 28 shows a partial, top elevation view of a septum including aplurality of structural elements;

FIG. 29 shows a schematic, side cross-sectional view of an access portincluding a septum exhibiting curvature;

FIG. 30 shows a top elevation view of one embodiment of a septum frame;

FIG. 31 shows a schematic, side cross-sectional view of one embodimentof a septum including the frame shown in FIG. 30 and another material atleast partially surrounding the frame;

FIG. 32 shows a schematic, side cross-sectional view of anotherembodiment of a septum including a frame that is at least partiallysurrounded by another material;

FIG. 33 shows a schematic, side cross-sectional view of yet anadditional embodiment of a septum including a frame that is at leastpartially surrounded by another material;

FIGS. 34 and 35 show a respective schematic view of different patternsthat may be generated by radiopaque material comprising a septum;

FIG. 36 shows a perspective view of one embodiment of an infusion setaccording to the instant disclosure;

FIG. 37 shows a perspective view of another embodiment of an infusionset according to the instant disclosure;

FIGS. 38 and 39 show a side cross-sectional view and an endcross-sectional view of one embodiment of tubing including an innerlayer and an outer layer;

FIG. 40 shows a schematic, side cross-sectional view of tubing includingan inner layer, an outer layer, and at least one reinforcing element;

FIG. 41 shows a schematic, side cross-sectional view of anotherembodiment of tubing including an inner layer, an outer layer, and atleast one reinforcing element;

FIGS. 42 and 43 show an end cross-sectional view and a schematic, sidecross-sectional view, respectively, of tubing including four layers;

FIGS. 44 and 45 show schematic, side cross-sectional views of a tubingsection including a plurality of layers, wherein at least one layer ofthe plurality of layers extends from a distal end of the tubing to forma slender hollow region for insertion through a septum of an accessport;

FIG. 46 shows a perspective view of one embodiment of an infusion systemconfigured for inserting a flexible catheter through a septum of anaccess port;

FIG. 47 shows a schematic, partial, side cross-sectional view of theinfusion system shown in FIG. 46;

FIG. 48 shows a perspective view of another embodiment of an infusionsystem configured for inserting a flexible catheter through a septum ofan access port;

FIG. 49 shows a schematic, partial, side cross-sectional view of theinfusion system shown in FIG. 48;

FIG. 50 shows a perspective view of the infusion system shown in FIG.48, wherein the insertion assembly is removed from the hub;

FIG. 51 shows a perspective view of one embodiment of an access portaccording to the instant disclosure;

FIG. 52 shows a top elevation view of the access port shown in FIG. 51;

FIG. 53 shows a simplified representation of a transverse cross-sectionof the access port shown in FIGS. 51 and 52;

FIG. 54 shows a schematic, side cross-sectional view of one embodimentof a septum including at least one gel region;

FIG. 55 shows a schematic, side cross-sectional view of anotherembodiment of a septum including at least one gel region;

FIG. 56 shows a schematic, side cross-sectional view of a furtherembodiment of a septum including at least one gel region;

FIG. 57 shows a side cross-sectional view of a first mold and a secondmold, wherein a gel region is positioned between the first mold and thesecond mold;

FIG. 58 shows a schematic, side cross-sectional view of an embodiment ofa septum including at least one chamber to capture a gel; and

FIG. 59 shows a schematic, side cross-sectional view of an additionalembodiment of a septum including at least one gel region.

DETAILED DESCRIPTION

One aspect of the instant disclosure relates to vascular access ports.More particularly, in one embodiment, the instant disclosurecontemplates that a vascular access port may be structured foraccommodating a fluid flow rate of at least about 1 milliliter persecond. Further, the instant disclosure contemplates that a vascularaccess port may be structured to withstand at least about 180 pounds persquare inch (psi) of pressure developed within the reservoir defined bythe septum and the access port housing. In one embodiment, an accessport may be structured for operating within a range of pressures ofabout 80 psi to about 180 psi. Such an access port may be advantageousfor use in infusing a fluid into a patient (e.g., infusing contrastmedia into a patient for CT or MR imaging).

Generally, an access port may comprise a housing that captures a septumthat may be repeatedly pierced or punctured with a hollow slenderelement (e.g., a cannula, or needle), which can include a Huber needle,a trocar with a circumferentially disposed cannula, or any othersuitable access mechanism, without limitation. The words “cannula” or“needle,” as used herein, encompass any slender element (e.g., acannula, a needle, a trocar, with a circumferentially disposed cannula,etc.) as known in the art or described herein, without limitation. Sucha septum may comprise a material (e.g., silicone) that seals, undersuitable compression, passages formed by puncturing the septum with suchan access mechanism. Thus, the septum may be at least partiallycompressed to facilitate closure of passages formed by puncturing theseptum with the access mechanism. The instant disclosure contemplatesthat the housing and septum may be structured so that a flow rate fromthe reservoir of the access port may be at least about 1 milliliter persecond without damaging the housing or septum or compromising thestructural integrity of the reservoir (e.g., causing the septum tobecome separated from the housing).

In one embodiment, an access port may comprise a cap and base whichdefine, in combination, a housing in which a septum may be positioned toform a reservoir. For example, FIGS. 1 and 2 show, respectively, anexploded perspective view and a side cross-sectional view of an accessport 50 including a base 56, a cap 54, a septum 80, and an outlet stem70. As shown in FIGS. 1 and 2, cap 54 and base 56, may be configured forcapturing a septum 80 between cap 54 and 56. Generally, cap 54 and base56 may collectively form a housing 60 for capturing septum 80 and atleast partially defining reservoir 66. Explaining further, cap 54 mayinclude an aperture 55 through which a portion of septum 80 may extendand base 56 may include a recess 57 configured to accept at least aportion of septum 80. Thus, a portion of septum 80 may be placed withinrecess 57 of base 56 and aperture 55 of cap 54 may be positioned aboutseptum 80 to collectively define a reservoir 66 within access port 50,the reservoir 66 being in fluid communication with a lumen of outletstem 70. In other embodiments, a plurality of reservoirs may becollectively defined by a housing and at least one septum, withoutlimitation. For example, any access port known in the art including aplurality of reservoirs (or one reservoir) may include any aspects) ofthe instant disclosure, without limitation. As shown in FIG. 1, aportion of outlet stem 70 may be positioned within and coupled to anaperture 58 formed within base 56.

Although FIG. 1 shows that access port 50 may include an outlet stem 70,other embodiments of access port 50 may not include an outlet stem 70.Therefore, FIG. 2 shows access port 50 without an outlet stem 70. Putanother way, the instant disclosure contemplates that access port 50may, optionally, include an outlet stem 70 or may be otherwiseconfigured. For instance, in one embodiment, outlet stem 70 may beformed as a part of with base 56, if desired. In another embodiment, acatheter may be operably coupled to the access port 50 (e.g., toaperture 58) without outlet stem 70. In yet a further embodiment, accessport 50 may simply include at least one outlet passage (e.g., aperture58) in fluid communication with the reservoir 66 and extending throughthe housing 60 and structured for allowing fluid flow through, ifdesired. As shown in FIG. 2, a portion of septum 80 may be positionedbetween cap 54 and base 56 and may be configured to withstand, withoutdamage or deforming to an extent that compromises the reservoir 66(i.e., blowing out), a selected magnitude of pressure developed withinreservoir 66.

For example, as shown in FIGS. 1 and 2, cap 54 may optionally include acircumferential ring structure 30 that is formed adjacent to a sideperiphery of septum 80. Ring structure 30 may be structured to inhibitdeformation of the cap 56 in response to a pressure developed withinreservoir 66 of access port 50. As shown in FIG. 3, in a top elevationview of cap 54, ring structure 30 may be generally circular. Further,ring structure 30 may be substantially congruent to a side peripheralshape of septum 80 or may exhibit a different shape than the sideperiphery of septum 80. In addition, the size of ring structure 30 maybe selected to provide a selected rigidity to a region of cap 54adjacent to of aperture 55 of cap 54. Such a configuration may inhibitdeformation of the cap 54 in response to pressure developed withinreservoir 66. For example, as shown in FIG. 2, a lateral thicknessT_(L), vertical thickness T_(V), or both may be selected for providing aselected rigidity to a region of cap 54 adjacent to a periphery ofseptum 80 (i.e., adjacent to aperture 55). In one embodiment, theoverall height H (FIG. 2) of access port 50 may be less than about 0.600inches.

In other embodiments, ring structure 30 may be generally rectangular,generally triangular, generally oval, generally polygonal, or of anothergeometrical shape, without limitation. For example, FIG. 4 shows a topelevation view of a ring structure 30 that is generally triangular.Further, FIG. 5 shows a generally rectangular ring structure 30.

Explaining further, housing 60 of access port 50 may comprise abiocompatible material such as polysulfone, titanium, or any othersuitably biocompatible material. Thus, cap 54 and base 56 may couple toone another generally along a mating line and may be secured or affixedto one another. More particularly, in one embodiment, both cap 54 andbase 56 may comprise titanium and may be welded, brazed, soldered, orotherwise affixed to one another. Such a configuration may providesuitable mechanical strength for capturing septum 80 between cap 54 andbase 56. Optionally, cap 54 and base 56 may be coupled to one another byat least one fastening element (e.g., at least one bolt, at least onescrew, at least one rivet, etc.), at least one adhesive, or acombination of such coupling mechanisms. Similarly, in one embodiment,outlet stem 70 and base 56 may each comprise titanium and may be weldedor otherwise bonded or coupled to one another.

In further detail, FIG. 6 shows an access port 50 implanted within apatient 67. In one embodiment, sutures may be used to affix the accessport 50 within the patient 67, if desired. After the housing 60 isimplanted in a patient 67, the upper surface of the septum 80 may begenerally flush or aligned with the surface of the skin surface 76 ofthe patient 67 and may be repeatedly punctured for creating apercutaneous passageway from the exterior of the skin of the patientinto the reservoir 66. The outlet stem 70 may create afluid-communicative passageway extending from the reservoir 66 andthrough the outlet stem 70, catheter 73, and into the interior of thepatient 67. Generally, catheter 73 may be coupled to the outlet stem 70for fluid communication with the reservoir 66 and for conducting fluidto a desired remote location from the reservoir 66 and within patient67. In one embodiment, catheter 73 may extend from the access port 50 toat least partially within a vena cava of the patient. Such aconfiguration may allow for infusion of a contrast media proximate tothe heart of a patient. Because such a contrast media may be harmful(e.g., radioactive or otherwise injurious) infusion directly into a venacava of a patient may reduce an overall quantity of contrast mediarequired to perform a selected imaging procedure.

As shown in FIG. 6, a cannula 90 may be inserted through the septum 80and fluid may be injected into the reservoir 66. For example, fluid maybe injected into reservoir 66 at a rate that causes pressure (i.e., apositive pressure) to be developed within reservoir 66. For example, apositive pressure, labeled “P_(R)” in FIG. 6, may develop withinreservoir 66 and may act upon the portion of septum 80 defining, inpart, reservoir 66. Such a pressure P_(R) acting on a portion of septum80 may develop force upon the septum 80. Likewise, force may bedeveloped on surfaces of the base 56 that are acted upon by pressure Pr.In one embodiment, cap 54 may be coupled to base 56 and structured tosuitably position septum 80 and couple septum 80 to housing 60 againstforce applied to the septum 80. Therefore, the septum 80, cap 54, andbase 56 may be structured for accommodating attendant forces developedby pressure P_(R). In one embodiment, access port 50 may be structuredfor accommodating (without damage) a pressure P_(R) of at least about185 psi with reservoir 66. In another embodiment, access port 50 may bestructured for accommodating (i.e., without damage) a range of pressuresof about 37 psi to about 65 psi with reservoir 66.

In further detail, during power injection, a fluid flow F may be causedto flow through cannula 90. A fluid flow rate (depicted in FIG. 6 byarrows labeled “F”) may be at least about 1 milliliter per second. Inanother embodiment, a fluid flow rate F may be between about 1milliliter per second to about 5 milliliters per second. During powerinjection, a pressure P_(i) may be developed within cannula 90 may be atleast about 30 psi. Accordingly, cannula 90 may be structured towithstand the forces associated with the above-discussed pressure, flowrate, or both. As discussed in further detail below, the cannula maycomprise a portion of an infusion set (e.g., a safety winged infusionset (SWIS)) or another infusion system configured for use with an accessport and a power injection system, without limitation.

More particularly, FIG. 7 shows a graph depicting pressure measurementsat different locations within an infusion system including an infusionset (as discussed in greater detail below) in fluid communication withan access port during infusion of a fluid at a rate of 5 milliliters persecond. As shown in FIG. 7, a pressure generally within a syringe barrelof a power injector may be about 265 psi. Further, a pressure generallyat the entrance of an infusion set may be about 225 psi and a pressuregenerally within a reservoir of an access port may be about 40 psi.Thus, the pressure drop through an infusion set may be about 185 psi. Asshown in FIG. 7, a pressure generally at the distal end of a catheterextending from the access port may be about 0 psi. Many factors mayinfluence a pressure (and a pressure drop) developed within an infusionsystem (e.g., infusion set, access port, etc.) during flow of a fluidthrough the infusion system, such as, for example, fluid viscosity,tubing inner diameter (i.e., lumen cross-sectional size), length of theflow path, and flow rate. Accordingly, as will be appreciated by theabove discussion of the access port 50 shown in FIGS. 1-3, such accessport 50 may be structured to accommodate a selected flow rate andassociated pressure P_(R) developed within reservoir 66 of access port50.

In another embodiment, the septum, housing, or both may be structured tomechanically secure or constrain at least a portion of the septum. Forexample, in one embodiment, the septum may include at least one couplingfeature configured to mate or couple with a complementary couplingfeature included by the housing. For example, male and female features(e.g., without limitation, ribs, flanges, interlocking features, tenonand mortise type features, tongue-in-groove features, T-slot features,dovetail features, snap-fit features, tabs and slots or other couplingfeatures as known in the art) may comprise the at least one couplingfeature included by the septum and the at least one complementaryfeature included by the housing, without limitation. “Tenon,” as usedherein, means a projecting member for at least partial insertion into amortise to make a joint. “Mortise,” as used herein, means a recess,hole, groove, or slot formed within a material for receiving at least aportion of a tenon to make a joint.

Generally, in one embodiment, the septum may include at least one tenonregion (i.e., at least one coupling feature) for coupling to acomplementary mortise region formed by the housing. Thus, the housingmay include a recess (i.e., at least one complementary feature) foraccepting at least a portion of the tenon region of the septum. Forexample, FIG. 8 shows a side cross-sectional view of one embodiment of aseptum 180 including a tenon region 270. Particularly, tenon region 270includes tapered surface 187 of septum 180, which may increase in height(i.e., from lower surface 183 of septum 180) along an increasing radialdirection (i.e., relative to a radial distance from a central axis ofseptum 180; that is, in a direction from rim 159 of cap 154 toward sidesurface 157 of base 156). Thus, as shown in FIG. 8, a height CG_(MIN) ofseptum 180 (measured at a radially innermost extent of tenon region 270)is less than a height CG_(MAX) of septum 180 (at a radially outermostextent of tenon region 270). Further, tenon region 270 may be acontinuous peripheral feature (i.e., an annular feature) of septum 180or may comprise one or more circumferentially separate regions, withoutlimitation. Further, as shown in FIG. 8, housing 160 (including cap 154and base 156) may generally define a complementary mortise region (e.g.,a circumferentially extending recess) for accepting at least a portionof tenon region 270. More particularly, a complementary mortise regionmay be defined by side surface 157 of base 156, lower flange surface 273of base 156, and tapered surface 172 of cap 154. Such a configurationmay secure, capture, or retain a portion of tenon region 270 of septum180 within the mortise region of housing 160 even if a selected maximumpressure is developed within reservoir 166 of access port 150.

In another embodiment, an access port may comprise a septum including atenon region including a plurality of tapered surfaces. For example,FIG. 9 shows a schematic side cross-sectional view of a septum 180including a tenon region 270 comprising tapered surface 187, taperedsurface 189, and tapered surface 191. Further, as shown in FIG. 9,housing 160 may generally define a complementary mortise region taperedrecess for accepting at least a portion of tenon region 270. Moreparticularly, a complementary mortise region may be defined withinhousing 160 by side surface 157 of base 156, lower flange surface 273 ofbase 156, tapered surface 172 of cap 154, tapered surface 193 of base156, and tapered surface 195 of cap 154. Such a configuration maysecure, capture, or retain at least some of tenon portion 270 of septum180 within a tapered recess of housing 160 even if a selected maximumpressure is developed within reservoir 166 of access port 150.

In summary, it should be understood that a portion of a septum maycomprise, generally, at least one tenon region for coupling with acomplementary mortise region formed in a housing. In another embodiment,generally, at least a portion of a housing may comprise a tenon forcoupling with a complementary mortise formed in a septum. As describedabove, a tenon region and a complimentary mortise region may compriseone or more tapered surfaces. In another embodiment, a tenon region andcomplementary mortise region may comprise a T-slot or other nontaperedgeometry, without limitation. For example, FIG. 10 shows a schematic,side cross-sectional view of one embodiment of an access port 150comprising a septum 180 including a tenon region 270. Further, acomplementary mortise region may be defined within housing 160 foraccepting at least a portion of tenon region 270. As shown in FIG. 10, amortise region may be at least partially defined by an annular extensionor protrusion 203 of base 156. Such a configuration may secure, capture,or retain at least a portion of tenon region 270 of septum 180 withinhousing 160 and suitably seal reservoir 166 even if an anticipatedmaximum pressure is developed within reservoir 166. It should be furtherunderstood that any of the tenon region and mortise region embodimentsshown in FIGS. 8-10 may be described in terms of extensions, ridges,protrusions, recesses, grooves, slots, etc., without limitation.

A further aspect contemplated by the instant disclosure relates tocoupling or affixing at least a portion of a peripheral region of aseptum to a housing. Such a configuration may maintain the integrity ofthe access port during use of the access port for infusing a fluid at aflow rate of at least about 1 milliliter per second. For example, in oneembodiment, at least a portion of a side periphery of a septum may beaffixed to at least a portion of a housing. FIG. 11 shows a sidecross-sectional view of an access port 50 wherein at least a portion ofa periphery of septum 80 adjacent to housing 60 is affixed to one orboth of cap 54 and base 56 adjacent to septum 80. More particularly, asshown in FIG. 11, a periphery of septum 80 (adjacent to cap 54 and base56) may include upper side region 97, upper annular region 93, lowerannular region 91, and lower side region 95. Thus, in one embodiment, anadhesive, (e.g., glue, epoxy, cement, tape, or any other adhesive asknown in the art) may affix at least a portion of one or more of upperside region 97, upper annular region 93, lower annular region 91, andlower side region 95 to the cap 54 or base 56, respectively. Such aconfiguration may secure septum 80 to housing 60 and may provide arelatively robust access port 50 suitable for power injection. It shouldfurther be appreciated that affixing at least a portion of a peripheralregion of a septum may encompass affixing at least a portion of a tenonregion (of either a septum or housing) to a mortise region (of either ahousing or septum), without limitation.

As described above, septum deformation is a design consideration withrespect to performing power injection via an access port. Further, oneaspect of the instant disclosure relates to a septum that isstructurally reinforced or otherwise limited against deformationexceeding a selected magnitude. More specifically, the instantdisclosure contemplates that at least one structural element may beconfigured to inhibit or limit deformation of a septum of an access portin response to pressure developed within a chamber or reservoir of theaccess port. Some embodiments of an access port including at least onestructural element for limiting deformation of a septum are disclosed inU.S. Patent Application No. 60/737,466, filed 15 Nov. 2005, thedisclosure of which is incorporated, in its entirety, by this reference.Any of the access ports encompassed by U.S. Patent Application No.60/737,466 may be structured for power injection.

In one embodiment, the instant disclosure contemplates that a septum maybe structurally coupled to a housing nonperipherally. Put another way,one aspect of the instant disclosure relates to coupling a nonperipheralportion of a septum to a housing of an access port. For example, FIG. 12shows one embodiment of an access port 110 according to the instantdisclosure including a cap 54 and a base 56 that capture a septum 120 toform a reservoir 66. Optionally, cap 54 may include a ring featureproximate to a periphery of the septum, as described above. In addition,outlet stem 70 may allow for fluid communication with reservoir 66 toperform infusion or fluid sampling processes. As shown in FIG. 12, astructural element 112 may extend between septum 120 and housing 60.More particularly, structural element 112 extends generally from lowersurface 121 of septum 120 to upper surface 165 of base 56. Thus, ifpressure (positive/negative) is developed within reservoir 66,structural element 112 may inhibit deflection or deformation of lowersurface 121 of septum 120 toward or away from upper surface 165 of base56. Generally, a structural element may inhibit deformation of a septumin relation to one or more selected directions (i.e., either toward oraway from upper surface 165 of base 56).

Generally, a structural element (e.g., structural element 112) maycomprise any of the following: at least one wire, at least one pin orcolumnar element, or at least one filament, without limitation. Such astructural element may comprise titanium, steel (e.g., stainless steel),polymers (e.g., DELRIN®, nylon, polyester, KEVLAR®,polytetrafluoroethylene (PTFE) (expanded or nonexpanded), polyurethane,etc.), or other materials as known in the art. In other embodiments, astructural element may comprise a composite, such as a fiber-reinforcedmatrix. In one embodiment, a structural element may comprise fibers(glass, carbon, etc.) dispersed or aligned within a silicone matrix.

Further, structural element 112 may be coupled to septum 120 by anadhesive, welding, snap-fitting, molding the septum 120 about a portionof the structural element 112, otherwise imbedding a portion ofstructural element 112 within septum 120, or as otherwise suitable.Similarly, structural element 112 may be coupled to base 56 by anadhesive, welding, or imbedding a portion of structural element 112within base 56. It may also be appreciated that, optionally, structuralelement 112 may exhibit a modulus of elasticity that exceeds a modulusof elasticity of septum 120. Such a configuration may allow forstructural element 112 to resist deformation of septum 120 in responseto a pressure developed within reservoir 66 (e.g., during a “powerinjection” process).

FIG. 13 shows a schematic cross-sectional view of an access port 110according to the instant disclosure including another embodiment ofstructural element 112. Particularly, as shown in FIG. 13, structuralelement 112 may include a barbed end 116, which is positioned at leastpartially within septum 120. Such a configuration may couple structuralelement 112 to septum 120 and may resist against deformation of theseptum 120 in response to pressure developed within reservoir 166.Furthermore, as shown in FIG. 13, the barbed end 116 of structuralelement 112 may, optionally, be pointed. Further, the point of barbedend 116 may be oriented toward upper surface 123 of septum 120. Such astructure may deflect a cannula that is inserted through septum 120 andcontacts barbed end 116 so that the cannula is directed away fromstructural element 112. Optionally, in another embodiment, structuralelement 112 may extend through base 56 and may be affixed to lowersurface 113 of base 56.

In another embodiment of an access port, a structural element may extendthrough a septum. For example, FIG. 14 shows a schematic, sidecross-sectional view of an access port 110 including a structuralelement 112 that extends from lower surface 121 of septum 120 to uppersurface 123 of septum 120. As shown in FIG. 14, structural element 112may also extend to upper surface 165 of base 56, to mechanically coupleseptum 120 to housing 60. Optionally, structural element 112 may includeat least one barb, which may be positioned within septum 120 andconfigured for coupling septum 120 to housing 60. In addition,structural element 112 may be affixed, if desired, to at least one ofupper surface 123 and lower surface 121 of septum 120. As may beappreciated, it may be advantageous for upper surface 123 of septum 120to be mechanically coupled to housing 60 to resist deformation of septum120 in response to a pressure developed within reservoir 66.

The instant disclosure further contemplates that a structural elementmay be employed in combination with a support element extending over aselected area of the upper surface of the septum. Such a support elementmay be positioned adjacent to an upper surface of a septum and may beconfigured to contact the upper surface of the septum with a selectedsurface area (e.g., when the septum deforms). For example, FIG. 15 showsa schematic, side cross-sectional view of an access port 110 including astructural element 112 that extends from housing 60 to an upper surface123 of septum 120. Furthermore, structural element 112 is coupled to asupport element 114, which is positioned adjacent to upper surface 123of septum 120. Such a configuration may provide a selected amount ofcontact area between support element 114 and upper surface 123 of septum120. Such a selected contact area between support element 114 and septum120 may reduce otherwise undesirably high stresses within septum 120when a pressure develops within reservoir 66 by distributing suchstresses over a selected area or region of septum 120. In addition,support element 114 may be observable (e.g., visually or by palpation)and, therefore, may be avoided when inserting a cannula through septum120. Additionally, the support element 114 can be used to identify theport 110 as being power injectable.

In another embodiment of an access port, a structural element maycomprise a portion of a septum affixed to a housing of an access port toresist deformation of the septum. For example, FIG. 16 shows aschematic, side cross-sectional view of an access port 110 including aseptum 120, which comprises an extension leg 124 (i.e., a structuralelement) that is coupled to housing 60. More particularly, as shown inFIG. 16, extension leg 124 may extend generally from lower surface 121of septum 120 to upper surface 165 of base 56. Extension leg 124 mayabut and may be affixed to upper surface 165 of base 56. Such aconfiguration may resist against deformation of septum 120 in responseto pressure developed within reservoir 166. In one embodiment, extensionleg 124 may be substantially centered (i.e., positioned generally at acentroid of lower surface 121) with respect to lower surface 121 ofseptum 120. Substantially centering extension leg 124 with respect tolower surface 121 of septum 120 may limit deformation of lower surface121 of septum 120 to a greater extent than other positions of extensionleg 124 may limit deformation of lower surface 121 of septum 120.Additionally, it should be appreciated that while FIG. 16 shows oneextension leg 124, the instant disclosure contemplates that at least oneextension leg (i.e., one or more extension legs) may extend from or becoupled to septum 120, without limitation. In another embodiment, atleast one extension leg may be coupled to a housing of an access port byan interference fit or a so-called “snap-fit.” More particularly, asshown in FIG. 17, extension leg 124 includes a bulbous or rounded end125 that is configured to fit within a recess 155 formed in base 56.Recess 155 may comprise an opening formed in upper surface 165 of base56 that is smaller than a maximum lateral dimension of rounded end 125,so that rounded end 125 may be forced through such an opening and “snap”into a portion of recess 155. Optionally, extension leg 124 may beaffixed (e.g., adhesively affixed, welded, pinned, or affixed by othersuitable methods to recess 155 formed in base 56. Such a configurationmay couple septum 120 to base 60 of access port 110 and may resist orlimit deformation of septum 120 in response to pressure developed withinreservoir 66.

Another aspect of the instant disclosure contemplates that at least aportion of an upper surface of a septum may be constrained or limited inits deformation. In one embodiment, at least one structural element maybe positioned upon or adjacent to an upper surface of a septum to limitdeformation of the septum in a direction toward the structural element.Put another way, at least one structural element may extend laterallyupon or adjacent to at least a portion of an upper surface of a septum.For example, FIG. 18 shows a schematic, side cross-sectional view of anaccess port 110 including a septum 130 and a structural element 132positioned adjacent to an upper surface 133 of septum 130. Optionally,structural element 132 may be bonded or affixed to upper surface 133 ofseptum 130. Structural element 132 may be structured to resistdeformation of septum 130 in a direction generally away from reservoir166.

In one embodiment, structural element 132 may substantially overlay orcover upper surface 133 of septum 130. Optionally, structural element132 may be at least partially embedded within septum 130. In oneembodiment, structural element 132 may be penetrable by a cannula (e.g.,a needle). In another embodiment, structural element 132 may cover aselected portion (i.e., at least a portion) of upper surface 133 ofseptum 130, which may allow for openings or apertures formed instructural element 132 through which a cannula may be inserted intoupper surface 133 of septum 130. It may be appreciated that, optionally,a modulus of elasticity of structural element 132 may exceed a modulusof elasticity of septum 130, so that deformation of septum 130 may beinhibited to a selected degree by structural element 132. Further,although a thickness (labeled “t”) of structural element 132 is shown inFIG. 18 as being substantially uniform, the instant disclosurecontemplates that a thickness “t” of structural element 132 may vary,without limitation. For example, thickness “t” of structural element 132may be maximum proximate to a centroid of the upper surface 133 ofseptum 130. In addition, as shown in FIG. 18, structural element 132 maybe positioned between cap 54 and septum 130. Structural element 132 maybe affixed to one or both of cap 54 and septum 130, if desired. Forexample, structural element 132 may be adhesively affixed, welded,mechanically fastened, or otherwise suitably coupled to one or both ofcap 54 and septum 130. Furthermore, structural element 132 may comprisea metal (e.g., titanium, steel, etc.), a polymer (e.g., DELRIN®polyurethane, nylon, etc.), or any other suitable material. In anotherembodiment, as discussed further below, structural element 132 maycomprise a relatively tightly woven fabric that resists tissue ingrowth(if positioned in potential contact with an internal cavity of thebody). In a further embodiment, a structural element 132 may comprise asubstantially fluffy or compressible polyester that may promote tissuehealing of punctures created by a cannula passing through septum 130 ofaccess port 110 (if positioned in potential contact with an internalcavity of the body).

In a further embodiment, the instant disclosure contemplates that atleast one structural element may be at least partially embedded within aseptum and may extend laterally through at least a portion of theseptum. For example, FIG. 19 shows a schematic, side cross-sectionalview of an access port 110 including a septum 120 and a structuralelement 140 extending laterally (i.e., across an opening in the housing60 closed by the septum 120) through the septum 120. As shown in FIG.19, structural element 140 may be affixed to housing 60 (e.g., cap 54 orbase 56). More particularly, as shown in FIG. 19, structural element 140may be affixed to cap 154 at connection regions 147 and 143. Inaddition, a selected level of tension may be developed within structuralelement 140, if desired, to provide for a desired level of resistance todeformation (i.e., flexibility) of septum 120. Such a configuration mayprovide a selected degree of resistance to deformation of septum 120 ina direction generally perpendicular to a direction of extension ofstructural element 140.

In another embodiment, a structural element may be positioned proximateto an upper surface of a septum to limit deformation of the septum. Forexample, FIG. 20 shows a schematic, side cross-sectional view of anaccess port 110 including a septum 130 positioned within a housing 60and a structural element 150 positioned proximate to an upper surface133 of septum 130. As shown in FIG. 20, structural element 150 extendslaterally over at least a portion of upper surface 133 of septum 130.Thus, structural element 150 may allow septum 130 to deform a selecteddistance (e.g., a gap labeled “G”) prior to contact with structuralelement 150. Further, structural element 150 may be affixed to cap 54and may be selectively tensioned to exhibit a selected degree offlexibility in response to contact between septum 130 and structuralelement 150. In one embodiment, structural element 150 may exhibit aflexibility or spring constant that exceeds a bulk flexibility or springconstant of septum 130 in response to a pressure developed withinreservoir 66.

In another embodiment, a structural element may be positioned proximateto or abutting a lower surface of a septum to limit deformation of theseptum. For example, FIG. 21 shows a schematic, side cross-sectionalview of an access port 110 including a septum 120 positioned within ahousing 60 and a structural element 170 positioned proximate to a lowersurface 121 of septum 120. As shown in FIG. 21, structural element 170may extend laterally over at least a portion of lower surface 121 ofseptum 120. Further, structural element 170 may be affixed to lowersurface 121 or septum 120 or otherwise coupled to lower surface 121 ofseptum 120. Thus, structural element 170 may inhibit deformation ofseptum 120. Further, structural element 170 may be affixed to base 56(or otherwise coupled to housing 60) to provide adequate resistance todeformation of septum 120. Optionally, structural element 170 may beselectively tensioned to exhibit a selected flexibility in response toforces applied to the structural element 170. Optionally, structuralelement 170 may exhibit a flexibility or spring constant that exceeds abulk flexibility or spring constant of septum 120.

Referring to FIGS. 18-21, it will be appreciated that structuralelements 132, 140, 150, or 170 may comprise, in some embodiments,elongated elements, such as, for instance, wire, ribbon, thread, fibers,columnar elements, or the like. Accordingly, such at least one elongatedelement may be arranged in a selected pattern adjacent or proximate toan upper surface of a septum. Further, in one embodiment, a structuralelement positioned proximate to or abutting a lower surface of a septum,proximate to or abutting an upper surface of a septum, or within aseptum, may comprise a mesh (e.g., a metal or plastic mesh, a fabric, afiber mesh, etc.). For instance, in one embodiment, a structural elementmay comprise a fabric comprising fibers or threads that seal against oneanother (e.g., fibers or threads coated with silicone). Such aconfiguration may allow for a cannula to pass through the fabric and forthe fabric to seal about the cannula, but may also allow for the fibersor threads to seal against one another when the cannula is removed. Inaddition, it will be understood that, based upon the instant disclosure,structural elements 132, 140, 150, or 170 as shown in FIGS. 18-21 may bearranged in a variety of configurations.

For example, FIG. 22 shows a partial top elevation view of oneembodiment of an access port 110, as shown in FIGS. 18-21, whereinstructural elements 132, 140, 150, 170 are arranged to form a generallytriangular shape or pattern. In a further example, FIG. 23 shows apartial top elevation view of an access port 110 as shown in FIGS.18-21, wherein structural elements 132, 140, 150, 170 are arranged intwo partially intersecting generally rectangular shapes or pattern. Inyet a further embodiment, FIG. 24 shows a partial top elevation view ofan access port 110, as shown in FIGS. 18-21, wherein structural elements132, 140, 150, 170 are arranged as a pattern comprising a firstplurality of substantially parallel lines and a second plurality ofsubstantially parallel lines, wherein the first plurality ofsubstantially parallel lines is substantially perpendicular to andintersects with the second plurality of substantially parallel lines. Inan additional embodiment, FIG. 25 shows a partial top elevation view ofan access port 110, as shown in FIGS. 18-21, wherein structural elements132, 140, 150, 170 are arranged as a pattern comprising twosubstantially straight (i.e., linear) members that intersect with oneanother. As shown in FIG. 25, structural elements 132, 140, 150, 170 maybe substantially perpendicular to one another. As shown in FIGS. 22-25,structural elements 132, 140, 150, 170 may be affixed to cap 54 atselected connection regions. Such configurations may allow for varyingdegrees of limitation of deformation of a septum, while allowing ampleaccess to a surface of a septum for perforation by a cannula (e.g., aneedle).

In another embodiment, the instant disclosure contemplates that astructural element may be at least partially embedded within a septumand may be in the form, configuration, or shape of a two-dimensional orplane (e.g., a circle, ellipse, triangle, rectangle, etc.) within theseptum. For example, FIG. 26 shows a partial top elevation view of aseptum 120 and a structural element 141 extending within the septum 120.In further detail, FIG. 27 shows a perspective view of a sectionedseptum 120 including a structural element 141 embedded within the septum120. As shown in FIGS. 26 and 27, in one embodiment, structural element141 may be generally circular. More generally, one or more structuralelements 141 may be at least partially embedded within a septum (e.g., aseptum 120 or 130, as discussed above), if desired. For example, aplurality of structural elements 141 may be embedded within a septum 120and arranged substantially concentrically with respect to one another,as shown in FIG. 28 in a partial, top elevation view. Structural element141 may be generally elongated (as shown in FIGS. 26-28) or may, moregenerally, exhibit a shape and size configured to resist deformation ofthe septum 120, without limitation. Thus, it should be appreciated thatone or more structural elements 141 may embody, for example, a washer ora disk that is frustoconical, domed, or otherwise shaped. In anotherembodiment, at least one structural element 141 may form, generally, atoroid. Further, at least one structural element 141 may exhibit atleast one selected characteristic (e.g., exhibiting a selected size,shape, elasticity, strength, etc.) to impart a desired level ofresistance to deformation (i.e., flexibility) of septum 120. Such aconfiguration may provide a selected level of resistance to deformationof septum 120 in response to a pressure developed within a reservoir ofan access port.

In another aspect of the instant disclosure, a septum may exhibit acurvature that resists deformation in response to a pressure developedwithin a reservoir of an access port. For example, FIG. 29 shows aseptum 120 including a generally concave upper surface 123 and agenerally convex lower surface 121. Explaining further, generallyconcave upper surface 123 and a generally convex lower surface 121 maybe exhibited by septum 120 in the absence of external forces (i.e., inan unstressed, equilibrium state). Such a configuration may provideresistance of the septum 120 to deformation due to a pressure developedwithin reservoir 66 of access port 110, because the upper surface 123 ofseptum 120 would be forced to flatten (i.e., via deformation of septum120) before extending beyond the upper surface of housing 60. In otherembodiments, a septum may be compressed (e.g., by way of a tenon andmortise coupling or another peripheral coupling configuration between aseptum and a housing) so that a curvature of the septum may be reducedor eliminated when the septum is assembled within the housing. However,such a configuration may increase the bulk flexibility or springconstant of the septum. Optionally, a structural element (as describedabove) may be included within the septum or upon a surface of the septumand may also be fabricated to exhibit concavity or convexity in theabsence of external forces. Such a configuration may facilitate afavorable compressive stress field within the septum when coupled to ahousing and may enhance resistance of the septum to deformation.

In a further configuration, a septum may include a structural frame orskeleton and a more pliant material configured to seal punctures createdby a cannula. More specifically, a frame may comprise a material with ashore A hardness of at least about 80. Optionally, a frame may include aplurality of whiskers, fibers, or particles to stiffen or strengthen theframe. In one embodiment, nylon fibers, barium sulfate, or the like maybe dispersed within a frame. Further, such a frame may be at leastpartially surrounded by a more pliant material exhibiting a Shore Ahardness of about 50 or less (e.g., a Shore A hardness of about 40 toabout 50). FIG. 30 shows top elevation view of a frame 178 including aplurality of spokes 179 extending from a generally common origin orregion as well as rings 181 and 185. As shown in FIG. 30, spokes 179 incombination with one or both of rings 181 and 185 form apertures 188.According to the instant disclosure, a relatively pliant materialconfigured to seal punctures formed by a cannula passing through thematerial may at least partially surround such a frame 178. For instance,FIG. 31 shows a schematic side cross-sectional view of septum 177comprising a frame 178 and another material 190 molded partially aboutframe 178. Thus, material 190 may substantially surround spokes 179 andmay extend within apertures 188. Further, as shown in FIG. 31, ring 181may form a tenon region 270 for coupling with a housing (as describedabove) as well as an upper septum surface 191 and a lower septum surface193. As may be appreciated with reference to shown in FIG. 31, duringuse, a cannula may pass through a continuous upper layer of material 190and a continuous lower layer of material 190. Such a configuration mayprovide suitable sealing capability for septum 177. It will beappreciated that many variations are contemplated by the instantdisclosure. For example, FIGS. 32 and 33 show side cross-sectional viewsof different embodiments of a septum 177 including a frame 178 andanother material 190 at least partially surrounding the frame 178. Thus,a frame and a material at least partially surrounding the frame mayexhibit arcuate or substantially planar surfaces and may be formed ofselected thickness and comprising selected materials (e.g., silicone,etc.).

In a further aspect of a septum according to the instant disclosure, aseptum may include a radiopaque material and may be configured to form aselected pattern when an x-ray is taken through the septum. For example,FIGS. 34 and 35 show schematic views of patterns 199 that may begenerated by correspondingly positioned radiopaque material within aseptum. Such a configuration may be useful for identifying the accessport as being capable of accommodating particular power injectionprocesses or for locating the septum of an access port.

The instant disclosure further contemplates that any infusion apparatusor device that is used in combination with an access port for infusingfluid at a rate of at least about 1 milliliter per second may beconfigured accordingly. For example, an infusion set for accessing avascular access port may include a needle or cannula for puncturing aseptum of the access port, a distal end for coupling to an injectionapparatus, and tubing (e.g., at least one tubing section) extendingbetween the cannula and the distal end. Generally, any componentscomprising an infusion set may be configured to withstand a selectedflow rate and associated pressure developed by such a selected flowrate.

FIG. 36 shows one embodiment of an infusion set 310 including a basemember 340, a cannula 350, a tubing section 314, and connector 312.Tubing 314 may be affixed or otherwise coupled to connector 312 and base342 generally at joints 313 and 339, respectively. Also, as shown inFIG. 36, a clamp device 316 may be suitably configured for allowing orpreventing fluid flow through tubing 314. Further, each of the basemember 340, cannula 350, tubing section 314, and end connector 312 maybe structured for accommodating a fluid flow rate of at least about 1milliliter per second through the infusion set 310. In further detail,tubing section 314 may exhibit sufficient strength for withstanding atleast about 200 psi without damage. Optionally, tubing section 314 maywithstand at least about 300 psi without damage. Further a pressure atwhich a portion of the infusion set bursts (i.e., a burst pressure ofthe infusion set 310) may be at least about 400 psi; optionally, such aburst pressure may be at least 600 psi. In one embodiment, tubingsection 314 may be substantially optically clear or may be at leastpartially transparent. In one embodiment, generally, tubing section 314may comprise a polymer, such as TECOTHANE®. More specifically, tubingsection may comprise a polymer, such as TECOTHANE® 55D or a polymer,such as TECOTHANE® 95A. For example, if tubing section 314 has an innerdiameter (i.e., a lumen) of about 0.048 inches (+0.003 inches) (i.e., 19GA), tubing section 314 may comprise a polymer, such as TECOTHANE® 55D.In other examples, if tubing section 314 has an inner diameter (i.e., alumen) of about 0.041 inches or 0.034 inches (+0.003 inches) (i.e., 20GA or 22 GA, respectively), tubing section 314 may comprise a polymer,such as TECOTHANE® 95A. Optionally, any polymer, such as TECOTHANE® typematerial may be at least substantially free of a plasticizer, such as,for instance, Di(2-Ethylhexyl)Phthalate (“DEHP”). In one embodiment,connector 312 may comprise polyvinylchloride (“PVC”) and may be,optionally, at least substantially free of plasticizer. The materialsdisclosed above are merely examples; more generally, tubing section 314,connector 312, base member 340, and cannula 350 may comprise anymaterial (e.g., thermoplastic, polyurethane, metal, etc.) suitable forproviding a robust and effective infusion set 310.

During use of the infusion set 310, a mechanical injector may beoperably coupled to connector 312 via fastening structure 311. Forexample, fastening structure may comprise a luer-type connection or anyother fluid connection structure. Thus, a fluid may be flowed throughthe infusion set at a flow rate of at least about 1 milliliter persecond via an injection apparatus. As discussed above, a pressure dropthrough the infusion set 310 may be at least about 100 psi; optionally,a pressure drop through infusion set 310 may be at least about 185 psi.

In another embodiment, an infusion set may include two connectors. Inone configuration, one connector may be structured for performing powerinjection and another connector may be structured for allowing syringeaccess. For example, FIG. 37 shows an infusion set 309 including a basemember 340, a cannula 350, a tubing section 324, an intermediateconnector 322, a tubing section 314, and an end connector 312. Tubing314 may be affixed or otherwise coupled to connector 312 and connector322 generally at joints 313 and 323, respectively. Similarly, tubing 324may be affixed or otherwise coupled to connector 322 and base member 340generally at joints 325 and 329, respectively. Infusion set 309 may bestructured for fluid flow rates and pressures as discussed above inrelation to infusion set 310. Accordingly, tubing sections 314 and 324may comprise materials (e.g., a polymer, such as TECOTHANE® and sizes asdiscussed above in relation to infusion set 310, without limitation.Similarly, connectors 312 and 322 may comprise any materials (e.g., PVC)discussed above in relation to infusion set 310, without limitation. Asshown in FIG. 37, a clamp device 316 may be suitably configured forallowing or preventing fluid flow through tubing 314. Likewise, clampdevice 326 may be suitably configured for allowing or preventing fluidflow through tubing 324. In addition, connector 312 may include afastening structure 311 (e.g., a luer connection, another threadedconnection, or any other fastening structure as known in the art) forreleasably affixing or coupling the connector 312 to an injectionapparatus. Also, connector 322 may include a fastening structure 321(e.g., a luer connection, another threaded connection, or any otherfastening structure as known in the art) for releasably affixing orcoupling the connector 322 to an injection apparatus.

Generally, the instant disclosure contemplates that, in one embodiment,connector 312 may be used for power injection, while connector 322 iscapped. In another embodiment, a valve mechanism may selectively allowflow through tubing sections 314 and 324 via fluid flow throughconnector 312, while preventing leakage from connector 322. In addition,if infusion set 309 is not being used for power injection, a capincluding a septum may be coupled to connector 322, connector 312, orboth. Such a configuration may allow for a syringe to puncture theseptum and infuse medication or remove a blood sample. Such aconfiguration may provide a convenient infusion set with separateconnectors for power injection and syringe access, respectively.

In a further aspect contemplated by the instant disclosure, tubing thatis used in connection with power injection may be structured forwithstanding a selected pressure during use (e.g., power injection) and,optionally, may be configured to resist kinking. Generally, the instantdisclosure contemplates that tubing may comprise a plurality of layers.In one embodiment, tubing may comprise a relatively high strength layerand at least one relatively flexible layer. Thus, any layers of tubingmay comprise PTFE, polypropylene, polyetheretherketone (“PEEK”),polyimide silicone, fluorinatedethylenepropylene (FEP), perfluoroalkoxy(PFA), ethylenetetrafluoroethylene (ETFE), polyurethane (e.g.,thermoplastic polyurethanes, including ISOPLAST®, TECOFLEX®, TECOTHANE®,CARBOTHANE®, TECOPLAST®, or TECOPHILIC® type polyurethanes), orcombinations of the foregoing. In one embodiment, the layers may bebonded to one or more adjacent layers. In another embodiment, each ofthe layers may be movable or slidable relative to one or more adjacentlayers.

For example, FIGS. 38 and 39 show a side cross-sectional view and an endcross-sectional view of tubing 401 including an inner layer 420 and anouter layer 422. Generally, at least one of inner layer 420 and outerlayer 422 may exhibit relatively high strength and the other of innerlayer 420 and outer layer 422 may be relatively flexible or vice versa.In one embodiment, inner layer 420 may exhibit relatively high strengthand may comprise, for example, PEEK, ULTEM®, polyimide, or the like.Further, outer layer 422 may be relatively flexible and may comprise,for example, FEP, PTFE, PEBAX®, ETFE, silicone or the like. Conversely,outer layer 422 may exhibit relatively high strength and may comprise,for example, PEEK, ULTEM®, polyimide, or the like, while inner layer 420may be relatively flexible and may comprise, for example, FEP, PTFE,PEBAX®, ETFE, silicone, or the like. Further, optionally, tubing maycomprise a first layer exhibiting a modulus of elasticity and at leastanother layer exhibiting a modulus of elasticity that is less than themodulus of elasticity of the first layer. For example, a relatively highstrength material may exhibit a modulus of elasticity of at least about400,000 psi. Furthermore, a relatively flexible material may exhibit amodulus of elasticity below about 390,000 psi. In another embodiment, atleast one of layers 420 and 422 may comprise a composite material (e.g.,a composite including particulate or fiber reinforcement). For example,in one embodiment, tubing may comprise polyurethane or PTFE includingglass or carbon reinforcing fibers or particles. In one embodiment, eachof the layers 420 and 422 may be movable or slidable relative to one ormore adjacent layers. Such a configuration may withstand a selectedinternal pressure without damage to the tubing and may also resistkinking.

In another embodiment, a reinforcing element may be incorporated withinat least one of the plurality of layers comprising tubing. For example,FIG. 40 shows a schematic side cross-sectional view of tubing 403including inner layer 430 and outer layer 432, wherein at least onereinforcing element 434 is incorporated within outer layer 432.Optionally, at least one reinforcing element 434 may be incorporatedwithin any layer or layers of a plurality of layers comprising tubing,without limitation. As shown in FIG. 40, reinforcing element 434 maycomprise a coil, in one embodiment. One of ordinary skill in the artwill appreciate that many variations are possible, for example, at leastone reinforcing element may comprise a mesh (e.g., a wire mesh, afabric, a fiber mesh, etc.). In another embodiment, at least onereinforcing member may comprise one or more elongated members extendinglongitudinally within at least one layer comprising tubing (e.g.,aligned with the direction of extension of the tubing). In anotherembodiment, at least one reinforcing member may comprise one or morerings. Such a configuration may provide radial stiffness, strength, orboth to a tubing section.

Referring to FIG. 40, in one embodiment, inner layer 430 may exhibitrelatively high strength and may comprise, for example, PEEK orpolyimide. Further, outer layer 432 may be relatively flexible and maycomprise, for example, FEP, PTFE, ETFE, silicone, or polyurethane.Further, layers 430 and 432 may have a thickness (e.g., a radialthickness) of between about 0.005 inches and about 0.001 inches. Asmentioned above, layers 430 and 432 may be bonded to one another or maybe movable (slidable, twistable, etc.) with respect to one another.Optionally, a coating 433 may be applied to at least a portion ofexterior surface of layer 432. Such a coating 433, in one embodiment,may comprise a polymer, such as TEFLON® and may have a thickness ofbetween about 0.001 inches and about 0.002 inches.

In a further embodiment, FIG. 41 shows a schematic side cross-sectionalview of tubing 405, including inner layer 440 and outer layer 442,wherein at least one reinforcing element 444 is incorporated withininner layer 440. As shown in FIG. 41, reinforcing element 444 maycomprise a coil, in one embodiment. In other embodiments, reinforcingelement may comprise any structure discussed above in relation toreinforcing element 434, without limitation. In addition, in oneembodiment, inner layer 440 may be relatively flexible and may comprise,for example, FEP, PTFE, ETFE, or polyurethane. Further, outer layer 442may exhibit relatively high strength and may comprise, for example, PEEKor polyimide. Further, layers 430 and 432 may have a thickness (e.g., aradial thickness) of between about 0.005 inches and about 0.010 inches.Optionally, a coating 443 may be applied to at least a portion ofexterior surface of layer 442. Such a coating 443, in one embodiment,may comprise a polymer, such as TEFLON® and may have a thickness ofbetween about 0.001 inches and about 0.002 inches.

In an additional embodiment, tubing may include four layers. Forexample, FIGS. 42 and 43 show a cross-sectional end view and a sidecross-sectional view of another embodiment of tubing 400. Moreparticularly, as shown in FIGS. 42 and 43, tubing 400 includes layers402, 404, 406, and 408. As shown in FIG. 42, layer 402 defines a lumen410. In one embodiment, lumen 410 may have a substantially circularcross-sectional shape and may exhibit a diameter of about 0.024 inches.In another embodiment, each of the layers 402, 404, 406, and 408 may bemovable or slidable relative to one or more adjacent layers. Inaddition, layer 402 may comprise a material exhibiting a relatively hightensile strength. Such a configuration may withstand relatively highpressures within lumen 410. For example, layer 402 may comprise PEEK,polyimide, etc. Typically, such relatively high strength materials mayexhibit a modulus of elasticity of at least about 400,000 psi.Furthermore, each of layers 404, 406, and 408 may comprise a materialthat is relatively flexible. Such layers 404, 406, and 408 may eachexhibit a tensile strength that is less than the tensile strength oflayer 402. For example, each of layers 404, 406, and 408 may comprise afluoropolymer, PEBAX®, polyethylene terephthalate (“PET”), silicone,etc. Typically, such relatively flexible materials may exhibit a modulusof elasticity below about 390,000 psi. However, any layers may comprisePTFE, polypropylene, silicone, FEP, PFA, ETFE, polyurethane (e.g.,thermoplastic polyurethanes, including ISOPLAST®, TECOFLEX®, TECOTHANE®,CARBOTHANE®, TECOPLAST®, or TECOPHILIC® type polyurethanes), orcombinations of the foregoing, without limitation.

In a further aspect of the instant disclosure, at least one layercomprising a tubing section may extend distally from a slender hollowstructure for accessing a reservoir of an access port through a septum.Put another way, at least one layer may extend from a tubing section andmay be structured for puncturing a septum of an access port. Forinstance, FIGS. 44 and 45 show a schematic side cross-sectional view oftubing 400, 401, 403, 405, and an access port 50. Tubing 400, 401, 403,405 (as described above) includes a slender hollow region 450. Further,slender hollow region 450 may be relatively stiff and suited forpenetrating a septum 80 of an access port 50, as shown in FIG. 45. Thus,a slender hollow region 450 extending from a distal end of tubing 400,401, 403, 405 (which comprises a plurality of layers) may form a needleor cannula for fluid communication between a lumen of tubing 400, 401,403, 405, and a reservoir 66 of access port 50. More particularly, aslender hollow region 450 may comprise one or more layers exhibiting arelatively high strength of relatively high-strength layers (e.g., PEEK)forming tubing 400, 401, 403, 405. In one embodiment, an innermost layerof tubing 400, 401, 403, 405 may form slender hollow region 450. Such aconfiguration may be advantageous and may, for example, reduce thecomplexity of manufacturing an infusion set.

Many different embodiments of vascular access apparatuses or infusionsystems may incorporate one or more aspects of the instant disclosure.Some embodiments of a vascular access apparatuses or infusion systemsare disclosed in U.S. Patent Application No. 60/675,309, filed Apr. 27,2005, the disclosure of which is incorporated, in its entirety, by thisreference. Any of the infusion systems, apparatuses, or methods, takenalone or in combination, described in U.S. Patent Application No.60/675,309, may be structured or otherwise suited for performing powerinjection (e.g., accommodating a fluid flow rate of at least about 1milliliter per second, without limitation).

For example, the instant disclosure contemplates that an infusion systemconfigured for establishing fluid communication between a flexible tubeand a reservoir of an access port may be structured for power injection.Such an infusion system may include a slender pointed element thatfacilitates placement of the flexible tube through a septum of theaccess port and is removable from the infusion system once the flexibletube is appropriately positioned.

Particularly, FIG. 46 shows in one embodiment an infusion system 510 inan exploded assembly view, including an insertion assembly 520, a safetyclip 530, a hub 540 flexible tubing 590, extension tube 570, clampdevice 560, and tube connector 580. In further detail, FIG. 47 shows apartial side cross-sectional view of infusion system 510. As shown inFIG. 47, insertion assembly 520 comprises a base 528 and a slenderpointed element 522 (e.g., a needle, a trocar, or a cannula) securedthereto. As shown in FIG. 47, slender pointed element 522 includes apointed end 525. In a particular embodiment, the instant disclosure mayutilize a slender pointed element having a “non-coring” pointed end(i.e., pointed end 525 is not “open” or hollow) to avoid damaging aseptum of a port into which the slender pointed element is inserted. Theslender pointed element 522 may comprise any conventional needle,trocar, or cannula material, such as a stainless steel (e.g., AISI 304stainless steel), or may, in another embodiment, comprise a relativelyhard plastic. In one embodiment, base 528 may be injection molded orotherwise formed about slender pointed element 522 to capture a portionof the slender pointed element within the base 528, as best seen in FIG.47. Further, base 528 may optionally include a recess 524 structured foraccommodating other mechanisms (e.g., safety clip 530), if such a recessis desirable. Base 528 may also, optionally, include a coupling feature526 (e.g., a protrusion) structured for coupling to a coupling feature544 (e.g., a recess) formed in hub 540. Hub 540, as shown in FIG. 47,may generally include hub body 550, manifold element 561, septum 548 andcap 546. In one embodiment, hub body 550 may comprise TECOFLEX® (e.g.,such as TECOFLEX® 85A-B20). Further, hub body 550 may define wingstructures 541 and 543 (FIG. 46), which may be configured for affixingthe hub to skin of a patient (e.g., by taping wing structures 541 and543 to a patient, adhesively affixing wing structures 541 and 543 to apatient, or otherwise affixing wing structures 541 and 543 to apatient). Wing structures 541 and 543 may be employed for manipulationof the hub, such as, for example, when inserting the slender pointedelement 522 and flexible catheter 590 into an implanted port or whenremoving the slender pointed element 522 from an implanted port. Hubbody 550 may optionally include a recess 542, if such a recess isdesirable. As shown in FIG. 47, recess 542 may have a retaining lip 559for retaining safety clip 530 therein, while long slender element 522 ispositioned through the safety clip, as discussed in further detailhereinbelow.

Hub 540 may be structured for allowing the slender pointed element 522of insertion assembly 520 to pass through the hub 540 and through septum548, which is positioned within the hub 540. Put another way, manifoldelement 561 may define a plurality of passageways and at least oneseptum 548 through which fluid communication with the plurality ofpassageways may be accomplished. Explaining further, a manifold element561 may be configured for housing septum 548 to provide a seal a port oropening of a plenum defined by manifold element 561. Optionally, a capelement 546 may be positioned to capture septum 548 between cap element546 and manifold element 561. Cap 546 may include an aperture 547 forallowing a slender pointed element to pass therethrough and throughseptum 548. Thus, slender pointed element 522 (e.g., an appropriatelysized trocar, non-coring needle, or non-coring cannula) may be insertedthrough and removed from septum 548 without compromising the ability ofseptum 548 to seal. Further, the presence of cap 546 may allow forso-called “power injection” to occur via manifold element 561, whereinpressures within manifold element 561, tubing 570, and flexible catheter590 may reach at least about 200 psi or higher. Septum 548 may bestructured according to any septum embodiments disclosed herein (e.g.,including at least one structured element, for performing powerinjection, etc.), without limitation.

As shown in FIG. 47, flexible catheter 590 may be affixed to manifoldelement 561 and extension tube 570 may be affixed to manifold element561. In one example, extension tube 570 and flexible catheter 590 may bechemically bonded to manifold element 561. In another example, anadhesive may affix extension tube 570 to surface 552 a part of manifoldelement 561. Similarly, an adhesive may affix flexible catheter 590 toinner surface 562 another port of manifold element 561. Further, the hubbody 550 may be formed (e.g., injection molded, cured, or otherwiseover-molded) over the manifold element 561 (and, optionally the septum548, the cap 546, or both) and at least a portion of the extension tube570 as shown in FIG. 47. In another embodiment, the hub body 550 may beformed over at least a portion of the flexible catheter 590, if desired.

Generally, as mentioned above, any tubing disclosed in the instantdisclosure may comprise a portion of infusion system 510. Further,tubing clamps and connection devices as known in the art, may beemployed for extension tubing 570, clamp device 560, and tube connector580.

Flexible catheter 590 may comprise any material that is suitable forpower injection. For example, in one embodiment, flexible catheter 590may comprise a polymer, such as TECOTHANE® (e.g., TECOTHANE® TT1055 D).As shown in FIG. 47, flexible catheter 590 may include an elongatedlumen therein. Further, flexible catheter 590 may have, proximate toopening 593 thereof, a transition region 595 wherein a cross-sectionalsize (transverse to the lumen 594) of the flexible catheter 590increases as a function of increasing distance from opening 593.Optionally, transition region 595 may include two distinct tapers,although the instant disclosure contemplates more generally that atleast one taper, at least one arcuate surface, or combinations thereofmay define transition region 595. Generally, at least one aperture(e.g., one or more than one) may be provided proximate opening 593 thatextends through the tubular body of flexible catheter 590 andcommunicates with lumen 594. As shown in FIG. 47, flexible catheter 590may include two apertures 592 in fluid communication with lumen 594.

As shown in FIG. 47, slender pointed element 522 may extend throughsafety clip 530, through aperture 547 of cap 546, and into flexiblecatheter 590. Slender pointed element 522 may be structured for allowingfluid communication within flexible catheter 590. More particularly,slender pointed element 522 may be sized so as to allow for clearancebetween the exterior of the slender pointed element 522 and the interior(i.e., the lumen) of the flexible catheter 590. In one embodiment,slender pointed element 522 may include at least one longitudinallyextending indentation (with respect to a nominal cross-sectional shapeof the slender pointed element 522). For example, slender pointedelement 522 may have a pointed end 525 and may include longitudinallyextending indentations extending along (i.e., along a longitudinal axisof) slender pointed element 522. In another embodiment, slender pointedelement 522 may be generally circular, and longitudinally extendingindentations may form a substantially triangular cross section of theslender pointed element 522 over the portion of the slender pointedelement that they are formed.

In a further embodiment, an infusion system may be structured so that aslender pointed element passes through an extension tube, a flexiblecatheter, or both. Explaining further, appropriate placement andconfiguration of a septum may allow for a slender pointed element topierce or pass into an extension tube, a flexible catheter, or both.FIGS. 48 and 49 show another embodiment of a hub 540 including recess542, sleeve 620, and septum 548. In addition, at least a portion of eachof extension tube 570 and flexible catheter 590 may extend partiallywithin hub body 550. Further, flexible catheter 590 extends partiallywithin extension tube 570. Put another way, flexible catheter 590 may atleast partially overlap with extension tube 570 and vice versa. Inanother embodiment, a single tubular element may extend through hub 540and function as both the flexible catheter 590 and extension tube 570,if desired. Further, optionally, septum 548 may at least partiallysurround a portion of extension tubing 570. Such a configuration mayfacilitate sealing of septum 548 upon removal of slender pointed element522 therefrom. Sleeve 620 may compress septum 548 so as to facilitatesealing of septum 548 upon removal of slender pointed element 522 fromthe region of the septum 620 that the sleeve 620 surrounds. Septum 548may be structured according to any septum embodiments disclosed herein(e.g., including at least one structured element, etc.) for performingpower injection, without limitation.

Further, FIG. 50 shows a perspective view of safety clip 530 positionedgenerally about pointed end 525 of slender pointed element 522. Safetyclip 530 includes legs 533 and 535 each having a curved end region,respectively, and a hole 534 sized for passing there through slenderpointed element 522. In further detail, initially slender pointedelement 522 may be passed through hole 534 and between legs 533 and 535may be positioned and configured so as to allow the slender pointedelement 522 to extend there past. Further, when the slender pointed 522element is positioned therein and safety clip 530 is positioned withinrecess 542, safety clip 530 may be sized so that it will fit within theretaining lip 543 (FIG. 49) of recess 542 (FIG. 49). However, legs 533and 535 may be biased so that if the pointed end 525 of the slenderpointed element 522 is moved toward hole 534 and does not extend pastthe curved end regions of the legs 533 and 535, legs 533 and 535 willmove toward one another to effectively capture the pointed end 525 ofthe slender pointed element 522. Safety clip 530 may comprise anyself-actuating device for capturing a pointed end 525 of a slenderpointed element 522. Such a safety clip 530 may reduce the chance ofinadvertent insertion of the slender pointed element 522 into anotherperson, particularly the medical practitioner that is installing andremoving the slender pointed element 522.

The instant disclosure further recognizes that because the consequencesof improperly pressurizing an access port (and a catheter affixed to theaccess port, if any) or an infusion set may be problematic, it may beadvantageous to provide at least one identification attribute tocomponents of an infusion system so that all of such components may besuitable for withstanding an anticipated maximum flow rate and pressureassociated with a selected infusion process. Put another way, an accessport that is configured for accommodating a flow rate of at least about1 milliliter per second may include at least one identificationattribute. Such an at least one identification attribute may be observed(e.g., visually, by palpation, ultrasonically, radiographically, etc.)or otherwise detected. The term, “identification,” as used herein and inconnection with any infusion devices (an access port, infusion set,etc.), means the ability to correlate selected information of interestwith a perceivable feature.

The instant disclosure contemplates that any of the identificationfeatures or attributes, taken alone or in combination, described in U.S.Patent Application No. 60/658,518, filed 4 Mar. 2005, may identify anaccess port as being structured for power injection. Also, embodimentsof an access port including at least one identification attribute aredisclosed in U.S. patent application Ser. No. 11/320,223, filed 28 Dec.2005, the disclosure of which is incorporated, in its entirety, by thisreference. The instant disclosure contemplates that any of theidentification features or attributes, taken alone or in combination,described in U.S. patent application Ser. No. 11/320,223 may identify anaccess port as being structured for power injection. Further, an accessport may be identified by a maximum rate at which fluid may safely beinfused. For example, at least one identification attribute may indicatethat an access port is configured for accommodating a fluid flow rate ofat least about 1 milliliter per second, without limitation.

Referring to an access port encompassed by the instant disclosure, atleast one attribute of a housing of an access port may provide at leastone identification attribute for identifying the access port as beingstructured for power injection at a rate of at least about 1 milliliterper second. In one embodiment, at least one physical attribute (e.g.,size, shape, etc.) of an access port may identify the access port assuitable for power injection or may identify a maximum flow rate orpressure that may be safely accommodated by the access port.

Thus, one aspect of the instant disclosure relates to a method ofidentifying an access port (e.g., subcutaneously implanted or otherwisesituated, without limitation) as being suited for power injection. Moreparticularly, an access port including a septum may be provided.Further, at least one attribute of the access port may be perceived. Inaddition, the subcutaneously implanted access port may be identified asbeing suitable for power injection in response to perceiving the atleast one attribute of the access port.

In one embodiment, at least one attribute for identification maycomprise at least one feature of an access port housing. In furtherdetail, FIG. 51 shows a perspective view of an assembled access port 50.As shown in FIG. 51, a side periphery 295 (e.g., one or more side wallsand, optionally, exposed surfaces of suture plugs 291) of access port 50may be generally triangular. Thus, cap 54 and base 56 may collectivelyform a generally triangular housing 60 of access port 50. Also, theinstant disclosure contemplates that side periphery 295 may taper orarcuately extend between an upper surface 61 of cap 54 and lower surface51 of base 56. As shown in FIG. 51, a transverse cross section (taken ina selected plane substantially parallel to lower surface 51, if planar,of base 56) of access port 50 may be larger proximate to lower surface51 of base 56 and may be relatively smaller proximate to an uppersurface of cap 54. FIG. 52 shows a top elevation view of the access port50 shown in FIG. 52 and illustrates a generally triangular shape definedby side periphery 295. Additionally, FIG. 53 shows a simplifiedrepresentation of a transverse cross section of access port 50. As shownin FIG. 53, side periphery 295 of access port 50 may define three sideregions 303 that extend between associated vertex regions 301. Inaddition, in one embodiment and as shown in FIG. 53, side periphery 295may define a substantially equilateral generally triangular shape. Asmay be appreciated, side regions 303 may arcuately extend betweenassociated vertex regions 301; thus, side regions 303 may form “sides”of a generally triangular shape. Further, although vertex regions 301are rounded, it will be appreciated that such vertex regions 301 form anintersection between adjacent side regions 303. Accordingly, it will beappreciated that the phrase “generally triangular,” as used herein,encompasses any generally three-sided geometry wherein adjacent sidesintersect at or within vertex regions, without limitation. For example,“generally triangular” encompasses three-sided polygons, circulartriangles, equilateral triangles, etc., without limitation.

Furthermore, in a further embodiment, at least one attribute foridentification may comprise a radiographic marker. More particularly, anaccess port may exhibit an observable pattern, symbol, marker, or otherindicium that indicates that the access port is structured foraccommodating a particular flow rate, pressure, or both. In anotherembodiment, at least one attribute for identification may comprise aperceptible aspect, such as a visually perceivable feature. For example,at least one color, at least one symbol, at least one typographicalcharacter (e.g., a letter, a number, etc.), a pattern, or any otherindicium that may be visually perceivable or otherwise perceptible maybe used. In a yet additional embodiment, an ultrasound detectablefeature may be incorporated within an access port. In a furtheradditional embodiment, an access port may comprise an RFID tag.

It will be appreciated that other equipment and devices (e.g., infusionsets, tubing, injectors, etc.) may be identifiable in relation to asuitable maximum flow rate or maximum pressure. For example, particularinfusion apparatuses may include one or more of the above-mentionedidentification attributes or features. Such a configuration may allowfor different components (e.g., tubing, needles, access ports,mechanical injectors, etc.) to be matched with one another. For example,substantially similar or matching identification attributes shared by apower injection apparatus, an infusion set, and an access port mayindicate suitability for use with one another to perform a selectedpower injection process.

Another aspect of identification of an access port may relate toidentification of a patient within which an access port is implanted.More specifically, a patient may be provided with an identification cardthat carries perceptible (e.g., visually, via magnetic strip, bar code,manually, or by other suitable mechanisms) information regarding animplanted port. Thus, such an identification card may be presented to ahealth care worker, the information carried by the identification cardmay be perceived, and the access port may be identified. Uponidentifying the access port, characteristics of the access port may beascertained, such as, for instance, a maximum flow rate, a maximumpressure, suitability for a particular procedure or procedures, etc. Inanother embodiment, a wristband or bracelet may be provided to a patientwithin whom an access port is implanted. In a further embodiment, a keychain including an information carrying device, such as, for example, amagnetic strip, a bar code, a computer readable media or device (e.g., acompact disk, “flash” memory, a disk drive, etc.), or any other suitableinformation carrying device. In another embodiment, a sticker containingthe port information can be applied to the chart of the patient. Infurther embodiments, labeling on the infusion set can be used toidentify the set as power injection compatible.

A further aspect of the instant disclosure relates to a septumcomprising a gel or viscous liquid. The term “gel,” as used herein,means a colloid with at least one solid component suspended within atleast one liquid component, wherein the solid particles (e.g., polymerparticles) are attracted or otherwise linked to one another (e.g.,entangled or cross-linked) by covalent, ionic, or dispersion (physical)forces. Thus, in one embodiment, a gel may be a colloid in which thesolid disperse phase forms a network in combination with the fluidcontinuous phase to produce a viscous or semi-rigid sol. A gel mayexhibit stress-strain behavior that is elastic, viscoelastic, orplastic, without limitation. The term “viscous liquid,” as used herein,means a liquid exhibiting a viscosity of about 20,000 centipoises orhigher.

One or more passageways formed through a septum positioned within ahousing to form an access port may allow for leaking of fluid throughthe one or more passageways if the reservoir of the access port ispressurized. The instant disclosure contemplates that a gel region maybe generally positioned between an upper surface of a septum and a lowersurface of a septum, to facilitate a cannula extending through theseptum from the upper surface to the lower surface to also pass throughat least a portion of the gel region.

For example, in one embodiment, a septum may include a gel that is atleast substantially surrounded by a body material. For instance, FIG. 54shows a schematic, side cross-sectional view of a septum 610 including abody 612 and a gel region 620 positioned within body 612. Gel region 620may be structured so that a cannula inserted through upper surface 614and extending through lower surface 616 will pass through a portion ofgel region 620. In one embodiment, gel region 620 may comprise asilicone gel. In another embodiment, a gel region may comprise aninitially an uncured liquid (i.e., has a relatively low viscosity) thatmay be cured to cause the liquid to form a gel. In a further embodiment,gel region 620 may comprise a viscous liquid, or a viscoelasticmaterial.

In one example, gel region 620 may comprise an elastomer, such as, DOWCORNING® 7-9600 Soft Filling Elastomer, Parts A & B, which iscommercially available from DOW CORNING Corporation of Midland, Mich. Inanother embodiment, gel region 620 may comprise Silicone Gel MED-6340,which is commercially available from NuSil Technology of Carpinteria,Calif. In yet a further embodiment, gel region 620 may comprise anelastomer exhibiting a Shore A hardness of about 20 to about 30, suchas, for instance, DOW CORNING® C6-515 Liquid Silicone Rubber, Parts A &B or DOW CORNING® C6-530 Liquid Silicone Rubber Parts A & B, either ofwhich is available from DOW CORNING Corporation of Midland, Mich.Further, optionally, body 612 of septum 610 may comprise a siliconematerial with a Shore A hardness of about 50 to about 60. In anotherembodiment, body 612 and/or upper surface 614 of septum 610 may comprisea silicone material with a Shore A hardness of about 60 to about 80.Optionally, body 612 and/or upper surface 614 of septum 610 may comprisea fluoropolymer (e.g., PTFE, etc.) or polyurethane.

One of ordinary skill in the art will understand that, upon removal of acannula extending through at least a portion of gel region 620, apassageway or channel formed through gel region 620 may rebound,recover, seal, or heal. Further, gel region 620 may seal passagewaysformed through body 612 and upper surface 614. For example, gel region620 may inhibit or prevent fluid leakage from a reservoir of an accessport through the septum 610 when a pressure within the reservoir exceedsan ambient pressure external to the access port (e.g., during a powerinjection process, any process for flowing a fluid through an accessport as described above, or any process for flowing a fluid through anaccess port as known in the art, without limitation). In addition, gelregion 620 may be formulated and/or body 612 may be structured so that acannula passing through septum 610 will resist transferring or removingany of the material comprising gel region 620 outside of a selectedboundary or envelope. In one embodiment, body 612 may be structured toremove a material comprising gel region 620 from a cannula passingthrough the body 612.

Any of the septum embodiments discussed herein may include at least onegel region. For example, FIG. 55 shows a schematic, side cross-sectionalview of a septum 611 including a body 612 and a gel region 620. Asdiscussed above, gel region 620 may be structured so that a cannulainserted through upper surface 614 and extending through lower surface616 will pass through a portion of gel region 620. Such a configurationmay provide a robust septum that resists leaking even if a multitude ofpassages are formed through the septum with a cannula. Furthermore,providing a septum comprising a gel may improve a sealing ability orquality of the septum. Accordingly, a septum including a gel materialmay exhibit a reduced thickness (i.e., from an upper surface to a lowersurface) in comparison to a conventional septum. For example, FIG. 56shows a septum 613 including a body 612 and a gel region 620, wherein athickness T is less than a conventional thickness of a conventionalseptum. In one embodiment, a thickness T of septum 613 may be about0.500 inches or less.

The instant disclosure contemplates a variety of different manufacturingmethods may be employed for forming a septum comprising a gel. Forexample, generally, a body of a septum may be formed to substantiallysurround at least one gel region or a recess or chamber may be formed bya septum body that is filled with a gel. In one embodiment, a gel regionmay be suspended within a mold for forming a body of a septum. Moreparticularly, FIG. 57 shows a schematic, side cross-sectional view of afirst mold 652 and a second mold 654, wherein gel region 620 ispositioned between (e.g., suspended) first mold 652 and second mold 654.As shown in FIG. 57, gel region 620 is positioned by a frame element630, which abuts parting surface 655 of second mold 654. As shown inFIG. 57, frame element 630 may be positioned by pins 606. In otherembodiments, frame element 630 may be suitably positioned, withoutlimitation. In a particular embodiment, parting surface 653 of firstmold 652 may be positioned proximate to parting surface 655 of secondmold 654 (i.e., parting surfaces 653 and 655 may be separated by frameelement 630) to form a chamber defined by cavity 658 and cavity 656.Further, a hardenable material (e.g., a curable material, such as acurable silicone, a thermoplastic, a resin, etc.) may be injected intothe chamber and hardened. Thus, the hardenable material may surround orencapsulate gel region 620 and may exhibit a geometry that iscomplimentary to cavities 656 and 658.

Generally, frame element 630 may be coupled to or affixed to gel region620. In one embodiment, frame element 630 may couple or engage at leasta portion of a periphery of gel region 620. In another embodiment, frameelement 630 may be substantially planar and gel region 620 may rest uponor may be formed upon frame element 630. Further, in one embodiment,frame element 630 may extend at least partially through gel region 620.Optionally, frame element 630 may cover or extend across mold cavity 656of second mold 654. In one example, frame element 630 may comprise amesh (e.g., a metal or polymer mesh, a fabric, a fiber mesh, etc.). Inanother example, frame element 630 may comprise a sheet or layer ofsilicone and may be, optionally, perforated. If frame element 630comprises a mesh or is perforated, fluid communication (of a hardenablematerial) between cavity 658 and cavity 656 may occur, which may bedesirable for avoiding shifting of gel region 620 and/or frame element630 during encapsulation. Once gel region 620 is encapsulated, selectedportions of frame element 630 may be trimmed or cut, if desired.

In another method of forming a septum including at least one gel region,a septum body may be formed to include at least one chamber, which maybe filled with a gel. For example, FIG. 58 shows a septum body 612defining chamber 621. Optionally, opening 623 may be defined by body612. Accordingly, a gel may be introduced within chamber 621 via theopening 623 and the opening, optionally, may be closed. For example, anuncured gel may be introduced within chamber 621. Further, the uncuredgel may be cured by heating or by other suitable methods. Such aconfiguration may form a gel region as described above in relation toFIG. 55. In one embodiment, chamber 621 may be formed by an airinjection molding process, a blow molding process or any other processknown in the art for creating a chamber 621 within body 612. In anotherembodiment, body 612 may be formed about a removable plug or filler(e.g., a silicone plug, steel, or aluminum insert). Such a plug orfiller may be coated with a nonstick coating (e.g., TEFLON®, silicone,or any nonstick coating known in the art). Thus, chamber 621 may beformed upon removal of the plug or filler. In other embodiments,portions of a septum may be formed, filled with a gel (or a liquidprecursor to a gel), and bonded to one another to form a septum. In afurther embodiment, body 612 may be initially formed and may enclosechamber 621 within body 612. In addition, body 612 may be cut to form anopening to allow chamber 621 to be filled with a gel. Such an opening ofbody 612 may be closed or sealed to capture or form a gel region. In yeta further embodiment, a solid body may be formed and a chamber may beformed by slicing the solid body. In such a configuration, filling thechamber may cause the solid body to deform to form a domed or raisedregion, if desired. It will be appreciated that many differentapproaches may be employed for forming a chamber 621 within body 612 andsubsequently filling the chamber with a gel.

In an additional embodiment, a septum may include a gel regionpositioned between a body and a layer of material bonded to or formedover at least a portion of the gel region and at least a portion of thebody. For example, FIG. 59 shows a schematic, side cross-sectional viewof a septum 615 including a body 632, a gel region 620, and a layer 626.As shown in FIG. 59, gel region 620 may be positioned within a recess633 formed in the body 632 and layer 626 may extend over a portion ofgel region 620 and a portion of body 632. One of ordinary skill in theart will understand that gel region 620 may be positioned or formedwithin recess 633 of body 632 and then layer 626 may be formed orpositioned over gel region 620 and body 632. Further, layer 626 may bebonded (e.g., adhesively bonded, bonded via curing, bonded via welding,or as otherwise known in the art) or otherwise affixed to body 632 tocapture gel region 620. In one embodiment, septum 615 may be formed by amultiple head (e.g., a two head) injection molding apparatus. Moreparticularly, such a molding apparatus may be capable of forming thebody 632, forming the gel region 620 within the body 632, and forming(e.g., over molding) the layer 626 over the gel region 620 and body 632by suitable mold configurations and material injections. Layer 626, inone embodiment, may comprise a silicone-based material exhibiting aShore A hardness of between about 60 and about 80. Body 632, in oneembodiment, may comprise a silicone-based material exhibiting a Shore Ahardness of between about 40 and about 50. Accordingly, during use ofseptum 615 (installed within a housing to form an access port) a cannulamay pass through layer 626, at least a portion of gel region 620, andbody 632. Such a configuration may facilitate positioning of a cannulaextending through layer 626, at least a portion of gel region 620, andbody 632.

While certain representative embodiments and details have been shown forpurposes of illustrating aspects of the instant disclosure, it will beapparent to those skilled in the art that various changes in the methodsand apparatus disclosed herein may be made without departing form thescope of the instant disclosure, which is defined in the appendedclaims. For example, other access port sizes and shapes may be employed;and various other embodiments structures may be employed for forming atleast one identifiable feature of an access port of the instantdisclosure. The words “including” and “having,” (including theirvariants) as used herein including the claims, shall have the samemeaning as the word “comprising.”

1. A method of power injecting a fluid through an access port,comprising: implanting in a patient an access port suitable for passingfluid therethrough at a rate of at least about 1 milliliter per second,the access port including a body defining a cavity, a septum, and anoutlet in fluid communication with the cavity; and flowing a fluidthrough an infusion set into the access port at a rate of at least about1 milliliter per second, the infusion set including a needle in fluidcommunication with a tubing, the tubing in fluid communication with aconnector, each of the needle, tubing, and connector constructed to havea burst pressure of at least about 100 psi.
 2. The method according toclaim 1, wherein the step of flowing fluid comprises injecting contrastmedia fluid through the tubing and needle to induce a pressure withinthe access port in the range of about 37 psi and about 65 psi.
 3. Themethod according to claim 1, wherein each of the needle, tubing, andconnector constructed to have a burst pressure of at least about 400psi.
 4. The method according to claim 1, wherein each of the needle,tubing, and connector constructed to have a burst pressure of at leastabout 600 psi.
 5. The method according to claim 1, wherein theimplanting step includes implanting an access port that is suitable forpassing fluid therethrough at a rate of between about 2 milliliters persecond and about 5 milliliters per second.
 6. The method according toclaim 1, wherein the step of flowing fluid comprises flowing fluidthrough the infusion set at a rate of at least 5 milliliters per second.7. The method according to claim 1, further comprising the step oflimiting deformation of the septum in response to a pressure developedwithin the reservoir by reinforcing the septum through inclusion of astructural element.
 8. The method according to claim 7, wherein the stepof limiting deformation comprises embedding the structural element inthe septum.
 9. The method according to claim 7, wherein the step oflimiting deformation comprises non-peripherally coupling the septum tothe housing.